begin quoting [EMAIL PROTECTED] as of Tue, Jan 22, 2008 at 03:05:03PM -0800: > On Tue, Jan 22, 2008 at 02:38:29PM -0800, Andrew Lentvorski wrote: [snip] > > Stack is slow. Registers are fast. Nobody computes using the stack > > unless they absolutely have to. Stack is really only used as a place to > > spill registers. > > > > Even all of those variables that C claims are going onto the "stack" are > > really only allocated in registers if the compiler can get away with it. > > So are you saying the way to build a fast CPU is to have as many registers as > possible to avoid the stack as much as possible?
No, because too many registers really slow the machine down when you have a context switch or function call. All those registers have to be saved off somewhere. The SPARC idea of a "register window" is really interesting here, at least for function calls. It's sort of a stack of registers.... -- I want all the registers I can use, plus one, You can have them back when my program is done. Stewart Stremler -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-lpsg
